fix: update child Vue instances

fixes #66

Author: eddyerburgh

src/wrappers/vue-wrapper.js

@@ -5,6 +5,7 @@ import { logEvents } from '../lib/log-events'
 
 function update () {
   this._update(this._render())
+  this.$children.forEach(child => update.call(child))
 }
 
 export default class VueWrapper extends Wrapper implements BaseWrapper {

test/unit/specs/mount/Wrapper/update.spec.js

@@ -11,6 +11,33 @@ describe('update', () => {
     expect(wrapper.findAll('.child.ready').length).to.equal(1)
   })
 
+  it('updates slot components', () => {
+    const SlotComponent = compileToFunctions('<div><slot></slot></div>')
+    const Parent = {
+      template: `
+        <SlotComponent>
+        <div :class="[{ 'is-on': on }, 'inner']"></div>
+      </SlotComponent>
+      `,
+      props: {
+        on: {
+          default: false,
+          type: Boolean
+        }
+      },
+      components: {
+        SlotComponent
+      }
+    }
+    const parentWrapper = mount(Parent)
+    const innerEl = parentWrapper.find('.inner')
+    expect(innerEl.hasClass('is-on')).to.equal(false)
+    parentWrapper.setProps({
+      on: true
+    })
+    expect(innerEl.hasClass('is-on')).to.equal(true)
+  })
+
   it('causes vm to re render, and retain slots', () => {
     const compiled = compileToFunctions('<div><slot></slot></div>')
     const wrapper = mount(compiled, { slots: { default: [compileToFunctions('<div class="test-div" />')] }})